90 replies to this topic

[No Pressure]

OK, besides the obvious "let Lassie dive in and buddy breathe for TImmy", here's the next question. I actually changed my dive ascent profile based on some data I read.
If you are at 100 ft max, and beginning your ascent on a no deco dive, what is your ascent profile/

[Walter]

I ascent at 1 foot every 2 seconds to 50 feet where I stop for 1 minute. I then continue at the same rate to 40 feet where I stop for 1 minute. I then ascend more slowly, 1 foot every 3 seconds, to 30 feet where I stop for 3 minutes. I then ascend at the same rate to 15 feet where I stop for 5 or more minutes.

[Walter]

Where is Timmy? What well? Lassie who? June Lockhart fantasies?

[Diverbrian]

Thirty ft/min. or slower to 50 ft.

One min stop.

Then, I try to go more slowly to twenty ft and hang for five or more minutes and drift up from there as slowly as I can manage.

If I am in warm water, I will come up and play on the reef during the ascent time and that makes the ascent very enjoyable. If one a wreck, well... ascent lines are boring to look at!

[WreckWench]

If one a wreck, well... ascent lines are boring to look at!

Not in NC....the cudas all hang at 20 ft in the shadow of the boat and you can have as many as 75 or more in schools EVERYWHERE!!

Oh did I mention that they are MUTANT barracudas!!! Just ask ZenKim and VAScubaGirl if you don't believe me!!!

[Diverbrian]

If one a wreck, well... ascent lines are boring to look at!

Not in NC....the cudas all hang at 20 ft in the shadow of the boat and you can have as many as 75 or more in schools EVERYWHERE!!

Oh did I mention that they are MUTANT barracudas!!! Just ask ZenKim and VAScubaGirl if you don't believe me!!!

Cool! Great photo op!

[Coo's Toe]

I ascent at 1 foot every 2 seconds to 50 feet where I stop for 1 minute. I then continue at the same rate to 40 feet where I stop for 1 minute. I then ascend more slowly, 1 foot every 3 seconds, to 30 feet where I stop for 3 minutes. I then ascend at the same rate to 15 feet where I stop for 5 or more minutes.

That takes way too long... I just inflate my wing at 100 feet when I'm ready to ascend. That way I can beat everyone back to the boat, and get a couple of martini's down while those other suckers are still waiting at 15 feet.

I've found that when I do this, sometimes I don't have to wait with the others on the boat for the slow, bouncy, ride home... they send a helicopter out to pick me up. Must be a prize for being the first one back, huh?

( was I supposed to be serious??? )

Seriously, one thing I've been noticing lately is that a lot of people I dive with do a safety stop with me and then want to rush to the surface when the three minutes are up. They wait on the surface staring down at me as I slooooooowly ascend from safety stop depth, taking another full minute or more.

The greatest pressure change is in the first 20 feet of water, so this is where we should be taking the slowest ascent rate possible, right?

[Walter]

Erin,

You are absolutely correct. Most divers pop immediately to the surface from their 15 ft safety stop. It should be a time to slow the ascent. A slow acscent from 15 ft requires better buoyancy control which may be part of the problem.

Walter

[Diverlady]

Ascend to half the max depth (50ft in this case) and hold for a 1 min stop. Proceed to somewhere between 15 & 20ft and hold for anywhere from 3-6 min and proceed to surface.

Timmy's? Tim Horton's?? I'm SO THERE!!! AND a Lassie Mog! Sweet!!
(Okay, so maybe only the Canucks will understand that one!)

Diverlady

Edited by Diverlady, 14 April 2004 - 06:36 AM.

[SuperDave]

Hooked on Tim Horton's!!! Kept us awake for two weeks straight.

1 ft/2 seconds to 50. Stop for one minute then ascend to 20' (same ascent rate) for one more minute. Then 3 min at 10'.

Dave

[WreckWench]

Erin,

You are absolutely correct. Most divers pop immediately to the surface from their 15 ft safety stop. It should be a time to slow the ascent. A slow acscent from 15 ft requires better buoyancy control which may be part of the problem.

Walter

You are absolutely right....as is Coo's Toe. I believe some recent DAN findings show that more people are getting bent and the only ascent violation they can find is that last 10-20ft. I've seen it way too many times in NC...and the sad part is that if you tell people about it they look at you strange as if they have no idea about what you are talking about.

[Laura]

These are all good points everyone. Thanks for sharing.

This is slightly off-topic (indulge me please)...
Does anyone else do a safety stop on no-deco dives? I do one on EVERY dive. I feel like it can't hurt, and it's ony a few minutes, so why not do it? Yet I am surprized that some people "don't want to bother with it" on a no-deco dive. I guess I'd rather err on the side of caution.

Opinions?

[Laura]

OK, besides the obvious "let Lassie dive in and buddy breathe for TImmy",

That Lassie was sure was one smart dog!! I'll bet she could even administer O2 to Timmy, drag him out of the well, dial 911 on his cell phone with her paw, and bark out his vitals to the medics when the arrived on site.

"What's that girl? (woof, woof) His BP is 120 over 80? (woof) Good girl, lassie!"

[WreckWench]

These are all good points everyone. Thanks for sharing.

This is slightly off-topic (indulge me please)...
Does anyone else do a safety stop on no-deco dives? I do one on EVERY dive. I feel like it can't hurt, and it's ony a few minutes, so why not do it? Yet I am surprized that some people "don't want to bother with it" on a no-deco dive. I guess I'd rather err on the side of caution.

Opinions?

Not off topic at all...in fact its on the money. EVERYONE should do a 3-5 minute safety stop...hence the name... as you are supposed to dive within no decompression limits anyway aka "no deco" unless you've received proper training to exceed those limits.

So people who foolishly blow off those 'safety' stops are increasing the risk of DCS in my opinion.

I have also noticed that once someone earns a manditory deco obligation of say 1-3 minutes that they typically clear that manditory deco obligation but then fail to add the extra safety margin of another 3-5 minutes which they would have done or should have done had they stayed within no decompression limits.

Anyone else notice the same thing?

[Coo's Toe]

A safety stop is not a required deco stop. We should all be doing them on every dive, especially on our deeper dives where we might be close to the edge of NDL limits. It's just good habit to do one every dive.

I even do a safety stop of rediculously shallow dives with 30 feet max depths, because it's a great chance to practice. Like I was saying about the very slooooow ascent in the last 20 feet of water? Taking the time to stop at 20 feet, then finish with a slow ascent, takes practice to achieve the precise buoyany control necessary. If you skip safety stops because you don't need them, you miss out on the chance to practice that level of buoyancy control in shallow water where the practice will benefit you most.

WW is right. If you have reached a manditory decompression stop, you should add a 3-5 minute buffer after clearing your required stop time.